Interesting cvb0rg, thank you for sharing. Are you saying that

return [i for i in l if not isinstance(i, str)] is more performant than this solution?

It's a tutorial, it's actually shorter than most online tutorials already ~~

Ok, readjusted to be as difficult as other languages, and being 8kyu... Is it good enough now?

There will only be one 'longest' word.

This isn't really enforced, but I don't think it makes enough difference.

What do you mean? This is what I see:

% Store the result inside 2nd argument. Good luck!
find_longest(String, Result) :- Result is 0.

What's missing?

Edit: never mind, I see it now...

My initial submission was correct, unlocked solutions to get an example, compared it to mine and it was exactly the same.

Frustrating

To much information to take in for 1 kata. I dont even know where to start